Glossary of useful renal (kidney) words
A
Abdomen = (commonly called the belly) is the body space between the thorax (chest) and pelvis.
Access for dialysis = three different types of access can be used for haemodialysis. They are called a fistula (arteriovenous fistula, AVF), a graft, and a haemodialysis catheter (‘line’). For peritoneal dialysis, the access is a catheter is a special tube that is inserted into your abdominal cavity.
ACE = abbreviation for an angiotensin-converting enzyme (ACE) inhibitor. These are blood pressure tablets that also reduce protein levels in the urine. Drug name ends in ‘pril’ (e.g. Ramipril). Similar to ARB.
Acute = a word meaning short-term and of rapid onset, usually requiring a rapid response – often reversible.
Acute kidney injury (AKI) = rapid onset of kidney failure. It is usually reversible.
Adequacy = a term that refers to how well dialysis is working. To measure adequacy, tests are carried out to see if enough fluid and waste products are being removed from the blood.
Albumin = a type of protein that occurs in the blood.
ALG = abbreviation for anti-lymphocyte globulin, a strong treatment against the rejection of a transplant kidney.
Altruistic donor = a kidney donor who gives a kidney for no material reward. This may be a family member, but may also include a living donor who gives a transplant to someone they have never met.
Alport = Alport syndrome is an inherited kidney disease. This means it runs in families and is caused by a genetic mutation. Men are more severely affected than women. It can lead to deafness as well as kidney failure.
Amyloidosis = the name for a group of rare, serious conditions caused by a build-up of an abnormal protein called amyloid in organs and tissues throughout the body.
Anaemia = a shortage of red blood cells, which leads to symptoms such as weakness, breathlessness and reduced energy. If due to CKD, it can be improved with iron and erythropoietin (EPO).
ANCA = is an abbreviation for anti-neutrophil cytoplasmic antibody. This is a type of antibody that is associated with types of vasculitis.
Angioplasty = the use of a balloon to stretch up the narrowing in a blood vessel during an angiogram. It can be part of a renal angiogram (for renovascular disease).
Ankle oedema = an abnormal build-up of fluid under the skin around the ankles. It is an early sign of fluid overload.
Artery = blood vessel that carries blood from the heart to the body
Antibody = a substance that normally helps the body to fight infection. They are made by white blood cells. After a transplant, antibodies can attack the new kidney and cause rejection. Antibodies also causes kidney diseases such as glomerulonephritis.
Antigen = type of protein that is found on the outer surface of the body’s cells.
ARB = abbreviation for angiotensin receptor blocker. These are blood pressure tablets that also reduce protein levels in the urine. Drug name ends in ‘-sartan’ (e.g. Losartan). Similar to ACE.
Arteriovenous graft (AVG) = similar to a fistula. However, instead of the artery being connected directly to your vein, a plastic tube is used to link the two together.
Artery = blood vessel that carries blood from the heart to the rest of the body.
Artificial kidney = another name for the dialyser (filtering unit) in a dialysis machine.
ATG = abbreviation for anti-thymocyte globulin, a strong treatment for rejection of a transplant kidney.
Azathioprine = an immunosuppressant drug that prevents the body from rejecting a transplanted organ. It is typically used with other drugs after a kidney transplant.
APD = abbreviation for automated peritoneal dialysis. A form of peritoneal dialysis that uses a machine to drain the dialysis fluid out of the patient and replace it with fresh solution. APD is usually carried out overnight whilst the patient sleeps.
B
Bacteria = a type of germ. Bacteria are microscopically tiny, single-celled organisms capable of independent life. Most are harmless, but some cause disease.
Beta-blocker = a drug used to control heart rhythm, treat angina, and reduce high blood pressure.
Bicarbonate = a substance that is normally present in the blood which is measured in the biochemistry blood test. A low blood level of bicarbonate shows there is too much acid in the blood.
Biochemistry blood test = a test that measures the blood levels of various different substances. Substances measured in people with CKD usually include sodium, potassium, urea, creatinine, glucose, bicarbonate, calcium, phosphate and albumin
Biopsy = a test involving the removal of a small piece of an organ or other body tissue and its examination under a microscope. The kidney is one organ that can be biopsied.
BK virus = not an abbreviation, just the name of a virus that can cause problems after transplantation
Bladder = organ where urine collects before being passed out of the body.
Blood cell = microscopic cell that makes up the solid part of the blood. There are three main types: red, white and platelets.
Blood level = a measurement of the amount of a particular substance in the blood, sometimes expressed in mmol/l (millimoles per litre) or µmol/l (micromoles per litre) of blood. For example, sodium is measured in mmol/L and creatinine measured in µmol/l.
Blood glucose = a sugar carried in the blood.
Blood group = classification system based on hereditary characteristics of the blood, i.e. whether or not a person has certain antigens on their cells. There are four blood groups: A, B, AB and O.
Blood pressure = level of pressure that the blood exerts against the walls of the arteries as it passes through them.
Blood vessel = tube that carry blood around the body. The main blood vessels are the arteries and veins.
Bone marrow = soft part in the middle of some bones, where blood cells are made.
BP = abbreviation for blood pressure.
Brain death = a term indicating that the entire brain has permanently stopped working, and that further life is possible only on a life-support machine. A person must be diagnosed brain dead before their organs can be removed for a deceased donor transplant.
Bright’s disease = an older name for glomerulonephritis. This term was used in the past before the different types of glomerulonephritis were given their own names.
C
Calcium = a mineral that strengthens the bones. It is contained in some foods, including dairy products. It is stored in the bones and is present in the blood. The kidneys normally help to keep calcium in the bones. In CKD, calcium drains out of the bones, and the level of calcium in the blood also falls.
Candida albicans = a fungus that sometimes causes peritonitis in patients on peritoneal dialysis.
CAPD = abbreviation for continuous ambulatory peritoneal dialysis. A continuous form of PD in which patients perform the exchanges of dialysis fluid by hand. The fluid is usually exchanged four times during the day, and is left inside the patient overnight.
Cardiologist = a medical doctor who specialises in diagnosing and treating conditions of the heart.
Catheter = a flexible plastic tube used to enter the interior of the body. A catheter is one of the access options for patients on haemodialysis. For patients on peritoneal dialysis, a catheter allows dialysis fluid to be put into and removed from the peritoneal cavity. A catheter may also be used to drain urine from the bladder.
Cell = tiny building block from which all living things are built up. Most cells have some common features (including a nucleus that is the cell’s control centre and an outer membrane or skin that gives the cell its shape). Cells in different parts of the body look different from each other and perform different functions (for example, skin cells are very different from blood cells).
Cholesterol = one of the fat levels in the blood. A high cholesterol value is a risk for getting heart disease or strokes. Diet and drugs can reduce levels of cholesterol.
Chronic kidney disease (CKD) = a long-term condition where the kidneys do not work as well as they should, or have an abnormal structure. It is graded into stages 1-5 – from minor to severe kidney disease.
This is a current simple(ish!) definition:
- Definition (simple): a gradual loss of renal function over months or years.
- Definition (more accurate but complex):
- An estimated or measured glomerular filtration rate (GFR) of <60 mL/min – that is present for at least three months with or without evidence of kidney damage; or,
- Evidence of kidney damage with or without decreased GFR – that is present at least three months, as evidenced by albuminuria (protein in urine), haematuria (blood in urine, after exclusion of urological causes), structural abnormalities (e.g. on renal ultrasound) or pathological abnormalities (e.g. on kidney biopsy).
Note. I.e. in some milder cases of CKD there is evidence of kidney damage but normal kidney function.
Ciclosporin = an immunosuppressant drug used to prevent the rejection of a transplant kidney.
Cinacalcet = a ‘calcimimetic’. A type of drug which is recognised by the body as if it is calcium (i.e. ‘mimics’ the effect of calcium). May be used to help lower the blood level of calcium in people with CKD and problems with a high calcium level in the blood.
CKD = abbreviation for chronic kidney disease.
Clearance = the removal of the toxic waste products of food from the body. Clearance is one of the two main functions of the kidneys. In the more advanced stages of CKD (Stages 4-5), clearance is inadequate and toxins from food build up in the blood.
Conservative care = treatment of end stage kidney failure (ESRF) without the use of dialysis. Alternative word to palliative or supportive care.
CMV = abbreviation for cytomegalovirus.
Creatinine = a waste substance produced by the muscles when they are used. The name creatinine is also given to a blood test that measures the blood level of creatinine. The higher the blood creatinine level, the worse the kidneys (or dialysis or a kidney transplant) are working. It should be 60-120 mcmol/L.
Creatinine clearance = a test done in addition to blood tests for measuring either kidney, dialysis or transplant function. The normal level for the kidney(s) is about 120 ml/min (1200 litre/week) whilst for CAPD patients it is 50 l/week, APD 65 l/week and Haemodialysis 100 l/week.
Cross-match = the final blood test before a transplant operation is performed. It checks whether the patient has any antibodies to the donor kidney. The operation can proceed only if the cross-match is negative (i.e. no antibodies are found).
CT scan = abbreviation for a computerised tomography scan. An investigation that uses a computer to build up a picture from a series of low-intensity x-rays.
Cystitis = a type of urinary tract infection (UTI) that causes inflammation of the bladder.
Cytomegalovirus (CMV) = a virus that normally causes only a mild ‘flu-like’ illness. In people with a kidney transplant (and in other people whose immune system is suppressed), CMV can cause a more serious illness, affecting the lungs, liver and blood.
D
DBD = abbreviation for ‘donation after brain death’, i.e. donation of a kidney from someone who has died, where death has occurred because of brain stem death (the person will need to be on artificial ventilation but their heart will still function).
DCD = abbreviation for ‘donation after cardiac death’, i.e. donation of a kidney from someone who has died as a result of their heart stopping beating.
Deceased donor transplant (DDTx) = transplant kidney that has been removed from a person who has died.
Dehydration = condition when there is not enough water in the body to enable it to function properly. Dehydration often occurs with low blood pressure, which causes weakness and dizziness.
Diabetes mellitus (DM) = a condition (also known as ‘sugar diabetes’ or simply as ‘diabetes’) in which there is too much glucose (sugar) in the blood. Whether diabetes is controlled by insulin, tablets or diet, it can cause ESRF. This happens most often to people who have had diabetes for longer than ten years. DM is the cause of ESRF in about 20% of all patients on dialysis.
Dialyser = the filtering unit of a dialysis machine. The dialyser removes body wastes and excess water from the blood in a similar way to a normal kidney. Also called an ‘artificial kidney’.
Dialysis = an artificial process by which the toxic waste products of food and excess water are removed from the body. Dialysis takes over some of the work normally performed by healthy kidneys. The name dialysis comes from a Greek word meaning ‘to separate’ – i.e. to separate out the ‘bad things’ in the blood from the ‘good things’.
Dialysis fluid = the liquid that provides the ‘container’ into which toxic waste products and excess water pass during dialysis for removal from the body.
Dialysis machine = the machine used to perform haemodialysis. It includes a dialyser, which filters the patient’s blood. The machine helps to pump the patient’s blood through the dialyser, and monitors the dialysis process as it takes place.
Dialysis membrane = a thin layer of tissue or plastic with many tiny holes in it, through which the process of dialysis takes place. In peritoneal dialysis, the patient’s peritoneum provides the dialysis membrane. For haemodialysis, the dialysis membrane is made of plastic. In each case, the membrane keeps the dialysis fluid separate from the blood (essential because dialysis fluid is toxic if it flows directly into the blood). However, the tiny holes in the membrane make it semi-permeable, allowing water and various substances to pass through it.
Diastolic blood pressure = a blood pressure reading taken when the heart is relaxed. It is taken after the systolic blood pressure and is the second figure in a blood pressure measurement.
Diffusion = a process by which substances pass from a stronger to a weaker solution. Diffusion is one of the key processes in dialysis (the other is ultrafiltration). During dialysis, body wastes such as creatinine pass from the blood into the dialysis fluid. At the same time, useful substances such as calcium pass from the dialysis fluid into the blood.
Diuretic = medical name for a water tablet. These drugs increase the amount of urine that is passed. Two commonly used diuretics are frusemide and bendroflumethiazide.
Donor = a person who donates (gives) an organ to another person (the recipient).
Donor kidney = a kidney that has been donated.
Doppler scan = a type of ultrasound scan (sound-wave picture) that provides information about blood flow through the arteries.
Dry weight = estimate of the body weight without any excess fluid in the lungs or in the tissues.
E
EBV = abbreviation for Epstein Barr virus (EBV), which can cause glandular fever in healthy people, and more serious problems in those who have received kidney transplants
ECG = abbreviation for electrocardiogram. A test that shows the electrical activity within the heart.
ECHO = abbreviation for echocardiogram. A type of ultrasound scan (sound-wave picture)that shows how well the heart is working.
eGFR = abbreviation of estimated glomerular filtration rate. Measurement of how much blood is filtered by the kidneys, calculated from the blood level of creatinine.
Endocrinologist = a doctor who specialises in treating disorders of the endocrine glands, including the pancreas. Hence look after patients with diabetes.
End-stage renal failure (ESRF) = a term for advanced chronic kidney failure (CKD5). People who develop ESRF will die within weeks (to three months) unless treated by dialysis or transplantation. These treatments control ESRF but cannot cure it. Once a patient has developed ESRF, they will always have it, even after a transplant.
End-stage renal disease (ESRD) = an alternative name for end-stage renal failure.
Established renal failure (ERF) = an alternative name for end-stage renal failure or end-stage renal disease.
EPO = abbreviation for erythropoeitin.
Erythropoeitin = a hormone, made by the kidneys, which stimulates the bone marrow to produce red blood cells. It is produced by healthy kidneys, but can be administered as an injection or tablet when the kidneys fail.
ESA = abbreviation for ‘erythropoeitin stimulating agent’, a group of drugs which act in exactly the same way as EPO but differ chemically so are given a slightly different name
ESRD = abbreviation for end-stage renal disease.
ESRF = abbreviation for end-stage renal failure.
Exit site = the point where a catheter comes out through the skin. Exit site infections can be a problem for PD patients.
F
Fistula (arteriovenous fistula, AVF) = surgically enlarged vein (usually located in the wrist or elbow) that provides access to the bloodstream for haemodialysis.
Fluid overload = condition in which the body contains too much water, caused by drinking too much, or not losing enough through diuretics or dialysis.
FK506 (or ‘FK’) = another name for tacrolimus. It is derived from the ‘working name’ for the drug in the early research trials.
G
Glomerulus = one of the 1 million tiny filtering units inside each kidney.
Glomerular filtration rate (GFR) = measures your kidneys’ ability to filter toxins or waste from your blood. It is usually expressed an an ‘estimated’ GFR (or ‘eGFR’). It is derived (estimated) from the blood creatinine level – the worse the kidney function, the higher the creatinine, the lower the GFR. If the GFR is low (less than 60 ml/min) there is chronic kidney disease. Normal GFR is 90-120 ml/min.
Glomerulonephritis (GN, nephritis) = painless inflammation of the tiny filtering units of the kidney (the glomerulus. This leads to progressive CKD in some cases. There are many different types and they are diagnosed after a kidney biopsy. Treatment with immunosuppressant drugs such as steroids may be used to reduce the kidney damage.
Glucose = type of sugar. There is normally a small amount of glucose in the blood. This amount is not increased in people with CKD unless they also have diabetes mellitus. Glucose is the main substance in PD fluid, drawing excess water into the dialysis fluid from the blood by osmosis.
Graft = a type of access for haemodialysis. The graft is a small plastic tube that connects an artery to a vein. It is inserted into the arm or leg by a surgeon. Haemodialysis needles are inserted into the graft, which can be used many hundreds of times.
H
Haemodialysis = treatment for kidney failure (ESRF/CKD5) where a dialysis machine and a special filter called an artificial kidney (or dialyser), are used to clean your blood.
Haemoglobin = substance in red blood cells that carries oxygen around the body.
HD = short for haemodialysis
Hormone = substance that acts as a chemical messenger in the body, controlling various body functions. Parathyroid hormone (PTH) is an example.
I
Ideal body weight = term describing the weight that people are expected to weigh based on age, sex and height.
Immune system = body’s ‘defence’ mechanism, that protects the body from infection, cancer and foreign bodies.
Immunosuppressant drugs = drugs used to suppress the immune system (and make it less effective), so that a transplanted kidney will not be rejected.
K
Kidneys = two bean-shaped organs that filter waste and excess water from the blood. The kidneys are located to the right and left of the spine, in the lower back. They send urine to the bladder through tubes called ureters
L
Living transplant (LTx) = transplant kidney that has been removed from a living person. They may be a living related transplant (LRTx) or living unrelated transplant (LURTx).
M
Malnutrition = loss of body weight, usually due to not eating enough foods that provide protein and energy.
Membrane = thin skin-like layer or film.
N
Nephritis = inflammation of the kidneys – sometimes used an abbreviation for glomerulonephritis.
Nephrologist (or renal physician) = a medical doctor who specialises in diagnosing and treating conditions of the kidneys.
Nephrology = study of kidney (or renal) medicine.
O
Oedema = abnormal accumulation of water in the body. When water accumulates in the lungs, this is known as ‘pulmonary oedema’.
P
Parathyroid hormone (‘PTH’) = a hormone produced by four small parathyroid glands behind the thyroid gland in the neck. The glands become overactive in more advanced CKD, and produce too much PTH.
Peritoneal dialysis = treatment for kidney failure (ESRF/CKD5) that uses the lining of your abdomen, or belly, to filter your blood inside your body.
PD = short for peritoneal dialysis
PD (Tenckhoff) catheter = tube which allows dialysis fluid to be put into, and removed, from the peritoneal cavity.
Peritoneum = natural membrane that lines the inside wall of the abdomen.
Peritoneal cavity = area in the abdomen that contains the stomach, liver and bowels.
Phosphate (‘PO4’) = mineral which is involved with calcium and builds up in advanced CKD.
Phosphate binder = medication that helps prevent a build-up of phosphate in the blood.
Platelet = type of blood cell that clots the blood.
Polycystic kidney disease (PCKD) = disease which runs in families and due to a problem in kidney development which leads to enlarged kidneys full of fluid filled sacs (cysts). It does not always lead to ESRF.
Potassium (‘K’) = salt that is normally present in the blood. Its level needs to be controlled because too much or too little can cause heart problems. It builds up in more advanced kidney failure.
Protein = one of the major types of foodstuff found in meat, fish, eggs, dairy produce and nuts. Protein is what makes up muscle and its waste products are got rid of through the kidneys. These substances are part of what makes people feel unwell in more advanced CKD
Pulmonary oedema = build up of fluid in the lungs which causes breathlessness, particularly when exercising or when lying flat.
R
Red cell = a type of blood cell that contains haemoglobin that carries oxygen around the body
Recipient = person who receives a transplant organ from a donor.
Rejection = process in which the body’s immune system recognises a transplanted kidney as ‘foreign’ and tries to remove it
Renal = related to the kidneys, e.g. renal (kidney) disease failure.
Renal transplant = operation to place a healthy kidney from a living or deceased donor into a person with kidney failure (CKD5).
S
Satellite haemodialysis unit = usually smaller unit that is located away from the main hospital renal unit.
Semi-permeable = describes a membrane that will allow some but not all substances to pass through it.
Sodium (‘Na’) = salt that is normally present in the blood. It is usually normal in kidney failure.
Supportive care = treatment of end stage kidney failure (ESRF) without the use of dialysis. Alternative word to palliative or conservative care.
Systolic blood pressure = a blood pressure reading taken when the heart is contracted. It is taken before the diastolic blood pressure and is the first figure in a blood pressure measurement.
T
Tissue type = set of inherited characteristics that are present on the surface of cells.
U
Ultrafiltration = removal of excess water from the blood.
Under-dialysis = not having enough dialysis.
Unit haemodialysis = having dialysis at the main hospital where your renal unit is based
Urea = one of the waste products that build up in the blood. The levels of urea in the blood is a measure of how well, or poorly, the kidneys are working. Similar to creatinine..
Ureter = tube that carry urine from the kidneys to the bladder.
Urethra = tube that carries urine from the bladder to the outside of the body.
Urinalysis (dipstick) = bedside test that checks several components of a urine sample – e.g. protein, infection, glucose, bilirubin, red and white blood cells.
Urine = fluid produced by the kidneys. It consists of excess water and waste products from food.
V
Vein = blood vessel that carries blood from the body back to the heart.
W
White cell = a type of blood cell that fights infection
This glossary includes words from the USA’s NKF glossary of renal related terms.
Last Reviewed on 6 June 2024